The present invention relates to tractor-drawn agricultural equipment. More particularly, this invention relates to an implement that converts between a wide, field traversing configuration to a narrower, road transport configuration by folding and unfolding. The foldable feature is useful on many types of implements, including but not limited to planters.
Various forwardly-folding agricultural implements or tool carriers are known and are aimed at meeting the dual and conflicting needs of being wide enough to work many rows in the field and narrow enough to be transported over roads. One such device is disclosed in U.S. Pat. No. 4,582,143 which issued to Pratt in 1986. The device has a central rear or trailing section supported by wheels. No ground working tools are carried by the central section. Left and right wing sections carrying tools are pivotally mounted to a telescopic tongue that also is connected to the rear section and the drawbar of the tractor. The telescopic tongue must extend as the wing sections are folded forwardly and inwardly for the transport mode. As a result, the overall length of the implement increases undesirably. The rear section then moves forwardly to counteract this tendency. Unfortunately, the telescopic tongue requires considerable precision to make and is subject to high maintenance requirements to ensure smooth, reliable action. The static and dynamic loads on the telescopic tongue can make its strength a significant design concern.
Therefore, a primary objective of the present invention is the provision of a wide-framed implement which can be closely coupled to the tractor in field operation for maneuverability and weight transfer, yet is foldable into a transport configuration which has a low center of gravity and narrow transport width.
Another objective of the present invention is the provision of a forwardly-folding agricultural implement or tool carrier which is an improvement over the existing forwardly-folding agricultural implements, especially those equipped with a telescopic tongue.
Another objective of this invention is the provision of a folding agricultural implement which does not rely on a telescoping tongue member.
Another objective of this invention is the provision of a folding agricultural implement which is compact in length and width in the transport position.
Another objective of this invention is the provision of a folding agricultural implement which can work a large number of rows in the field position.
Another objective of this invention is the provision of a folding agricultural implement which has front-mounted wing section wheels and allows the wing sections to be folded relatively tightly together in the transport position.
Another objective of this invention is the provision of a folding agricultural implement which is adaptable to being drawn by a three-point hitch so as to achieve a smaller turning radius and greater maneuverability.
Another objective of this invention is the provision of a folding agricultural implement which has lifting gage wheels that move with respect to the wing support in order to make room for the other lifting gage wheel in the transport position.
Another objective of this invention is the provision of a folding agricultural implement which can be raised and lowered in a level manner in both the transport and field positions.
Another objective of this invention is the provision of an agricultural implement having caster wheels which are hydraulically raisable and pivot about a vertical axis.
Another objective of this invention is the provision of an agricultural implement wherein some of the wheels are lockable in a desired pivot position, such as parallel to the direction of travel.
Another objective of this invention is the provision of an agricultural implement having hydraulically operated latches for securing the wing sections in either the field or transport position.
Another objective of this invention is the provision of a method of folding the wing sections of an agricultural implement with respect to a center frame and latching them in field and transport positions.
These and other objectives will be apparent to one skilled in the art from the drawings, as well as the description and claims which follow.